Move Character Limb based on Main Camera's Y Axis

I have a rigged model, and I'm attempting to make my rigged characters arm move up or down based on the camera's Y angle. When attempting to do so, the arm breaks and twists, some scary stuff. My code for it is pretty simple but stumps me. #pragma strict private var cameraY: float; private var rarmY: float;

 var rarm: GameObject;
 var cam: GameObject;
 
 function Update () {
     cameraY = cam.transform.eulerAngles.y;
     rarmY = rarm.transform.eulerAngles.y;
     rarm.transform.eulerAngles.y = cameraY;
 }

Any idea why this isn't working? I have the forearm as the rarm var, and the camera as the cam var.